Organic strategy for the management of sheath blight disease of rice
| dc.contributor.advisor | Sajeena, A | |
| dc.contributor.author | Karthika, S R | |
| dc.contributor.author | KAU | |
| dc.date.accessioned | 2019-12-23T06:15:37Z | |
| dc.date.available | 2019-12-23T06:15:37Z | |
| dc.date.issued | 2017 | |
| dc.description | PG | en_US |
| dc.description.abstract | The study entitled “Organic strategy for the management of sheath blight disease of rice” was undertaken at the Department of Plant Pathology, College of Agriculture, Vellayani and IFSRS, Karamana during 2015-2017 with the objective to develop an eco-friendly disease management package for sheath blight disease of rice using organic preparations, botanicals, soil amendments and non-hazardous chemicals. Seven isolates of Rhizoctonia solani was isolated from sheath blight infected rice plants collected from seven different rice growing tracts of Thiruvananthapuram district during Kharif, 2016. The symptoms of the disease were observed during the active tillering stage of the crop. Pathogenicity was confirmed by proving Koch’s postulates. The isolate collected from Karode (I6) took seven days and the other six isolates took three days for symptom development. Virulence rating by artificial inoculation on potted plants proved that the isolate collected from Attingal (I2) produced the maximum number of infected tillers (4.66) as well as the maximum relative lesion height at 5th (9.20%), 7th (15.70%), 10th (19.03%) and 15th (20.96%) days after inoculation. Thus, I2 was found to be the most virulent isolate. Based on the morphological and cultural characteristics, the pathogen was identified to be Rhizoctonia solani Kuhn (Accession no: KX674527). Further, molecular identification by ITS (Internal Transcribed Space) sequencing revealed 100 per cent similarity with R. solani AG-1 IA isolate CSU8. In vitro pathogen suppression studies revealed that fermented egg-lemon juice extract (10%), panchagavya (5%), garlic extract (10%), potassium silicate (1%), lime (12.5%) and fermented weed (Setaria barbata) extract (100%) resulted in 100 per cent inhibition of the mycelial growth of R. solani. Dipping sclerotia for 24 hours in fermented egg-lemon juice extract (10%), panchagavya (5%), lime (12.5%) and fermented weed (Setaria barbata) extract (100%) resulted in complete (100%) suppression of mycelial regeneration from sclerotia. Analysis of the major nutrients (N, P, K) and pH of the various treatments revealed that fermented weed extract, fermented egg-lemon juice extract and panchagavya were highly acidic (pH of 4.9, 4.5 and 4.2 respectively). The total N content was high in panchagavya (0.02 %) followed by fermented egg-lemon juice extract (0.01%) whereas the total K content was high in panchagavya (0.03%) followed by potassium silicate (0.01%). The P content was comparatively high in panchagavya (0.007%) followed by fermented egg-lemon juice extract (0.006%). The pot culture experiment for the management of sheath blight in rice (var. Uma) revealed that the maximum suppression of the vertical spread of the disease was observed in fermented egg-lemon juice extract (79.43%) and garlic extract (79.36%) sprayed plants which were found to be on par with the fungicide check, hexaconazole (79.36%). The percentage horizontal spread was the least for fermented egg-lemon juice extract (11.12%) and potassium silicate (16.93%) sprayed plants which were also on par with the fungicide check (10.44%). However, the highest grain yield was recorded in the plants sprayed with fermented weed (Setaria barbata) extract (15.98g) followed by fermented egg- lemon juice extract (15.33g) and garlic extract (14.66g) sprayed plants. Analysis of the major nutrients in the plants at the time of harvest revealed that the total N content was the maximum for the plants sprayed with garlic extract (1.645%) whereas the total K content was the maximum for the plants sprayed with potassium silicate (3.601%). Thus, the present study revealed that three treatments viz., fermented egg- lemon juice extract (10%), potassium silicate (1%) and garlic extract (10%) resulted in improved biometric and yield attributes of rice plants as well as in the reduction of sheath blight disease incidence. However, four foliar sprays at 45th, 60th, 75th and 90th DAS of potassium silicate at one per cent concentration was found to be the most economical and effective treatment in improving the yield as well as in reducing the sheath blight disease incidence and was found to be on par with the fungicide check. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810138203 | |
| dc.keywords | Plant Pathology, disease of rice | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 100 | en_US |
| dc.publisher | Department of Plant Pathology, College of Agriculture, Vellayani | en_US |
| dc.sub | Plant Pathology | en_US |
| dc.subject | null | en_US |
| dc.theme | disease of rice | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Organic strategy for the management of sheath blight disease of rice | en_US |
| dc.type | Thesis | en_US |